This is a multicenter, NIH-sponsored treatment trial of ursodeoxycholate (UDCA) plus methotrexate (MTX) or placebo in the treatment of primary biliary cirrhosis. Patients will be followed for six years on combined therapy. The endpoints of the study will be patient well-being, laboratory parameters, evidence of hepatic decompensation, histologic changes, need for liver transplantation, survival, and toxicity and safety.